Mainframe is an alternate universe version of Vision, played by Paul Bettany in "The Avengers" films. In the future of "Guardians of the Galaxy," Vision evolves to be the operating system of an entire planet.

Dave Bautista, who plays Drax, seemed to confirm the news to The Huffington Post, saying, "I heard that she's uncredited and a voice somewhere."

This also falls in line with some teasing banter between director James Gunn and Marvel boss Kevin Feige, who debated revealing the identity of Mainframe. "I blew it, I told one person," Gunn said. Feige responded, "It'll get out."